Wayne Laroche: Wildlife and high rivers: We can rebuild and repair Vermont's waterways

Sep. 25, 2011

Written by

Wayne Laroche

Irene’s floods brought tragic losses to many property owners and disruption of all sorts. Flood waters ripped out roads, bridges and other elements of the state’s infrastructure that will be costly to repair. It even drove the Agency of Natural Resources regulators responsible for the protection of the state’s waters from their headquarters in Waterbury. The personal and public costs associated with the floods will indeed be great. This is unfortunate to say the least. We can empathize for those who have endured loss.

Irene’s floods brought tragic losses to many property owners and disruption of all sorts. Flood waters ripped out roads, bridges and other elements of the state’s infrastructure that will be costly to repair. It even drove the Agency of Natural Resources regulators responsible for the protection of the state’s waters from their headquarters in Waterbury. The personal and public costs associated with the floods will indeed be great. This is unfortunate to say the least. We can empathize for those who have endured loss.

Although there is no good time for a disaster, this one comes at time when the state and its citizens are in no sense flush with money. Could there be any “silver lining” in this event? Perhaps there will be if state and town officials have the foresight to consider, choose and use better practices than they have in the past as they repair the flood damage. Band-aids and replacement of poor designs from the past will only ensure that the next flood brings similar destruction.

This is a golden opportunity to restore some of the integrity of our stream systems by sizing and choosing designs of culverts and bridges to better accommodate high stream flows as well as fish and wildlife passage. Simply avoiding the channelization of rivers by heavy equipment is a good start. If you want to learn about Vermont streams, the following VTANR website is a good place to start: http://www.vtwaterquality.org/rivers.htm.

For information of culverts and road crossings, try the state’s publication Guidelines for the Design of Stream/Road Crossings for Passage of Aquatic Organisms in Vermont found here: http://bit.ly/qiN4lJ.

The flood caused stream channel changes such as new meanders and pools, deposition of large boulders, gravel and woody debris are part of the naturally healing process of the stream that only occur when waters run swift. Some might think that these are not pleasant to the eye. However, like the scabs that form on fresh wounds they promote healing and future beauty. Hopefully, the coming “repairs” won’t just tear off these scabs.

Vermont’s river and stream systems have been literally ripped apart and destroyed in the past two hundred years by the activities of man. Salmon and sturgeon runs are gone from the lower rivers because of dams block passage, sediments cover spawning beds, and water temperatures exceed tolerance limits. Brook trout that abounded nearly every Vermont stream in the state are mostly relegated to life in headwaters where the waters are clearer and temperatures still run cool.

Most of the stream bank and channel destruction took place between 1800 and 1850 when the landscape went from being more than 90% forested to being less than 30% forested. The trees were cut for lumber or burned. Sheep were grazed to the tops of the mountain ridges eating vegetation down to the roots. River bottomlands were cleared to the edge of stream. Ditches were dug to drain the land. Beavers were driven to extinction in Vermont.

Denuded of forest vegetation, devoid of headwater beaver dams and ditched to facilitate speedy drainage of croplands, Vermont’s hills and mountains shed water faster and with greater ferocity than ever before. In some places, large boulders were even blasted out of stream channels to speed the “driving” of logs downstream to mills. Trees and large woody debris were pulled from stream channels to keep these clear of millworks and low bridges.

With fewer trees, logs, root wads and large boulders to dissipate energy and slow the flow, the power available to destroy stream banks and human infrastructure increased drastically. At the same time, the soil being carried by the speeding water encouraged additional erosion downstream. The result was erosion of a terrible magnitude. As a result, Vermont stream channels are 25-50% wider than they should be and more prone to flash flooding.

By the 1840’s, streams that once provided year round power for small mechanical saw and gristmills were no longer usable because of extended periods of very low flow. Even with the Green Mountains once again covered with forest mountain brooks still show clear signs of past abuses.

The Agencies of Natural Resources and Transportation as well as town selectboards and road crews now have an opportunity to try some new techniques and build smarter for a better future. Let’s hope and encourage them to build smarter, not just faster. Our streams and our natural resources are likely to provide greater benefits and fewer disasters if they do.

Wayne Laroche is the former Vermont Department of Fish & Wildlife Commissioner, having served for eight years in the position. A fishing biologist by training, Wayne is now currently assisting the Lake Champlain conservation organization Lake Champlain International with aquatic and fisheries issues as their Staff Scientist.